Abstract: A trench silicon carbide metal-oxide semiconductor field effect transistor includes a silicon carbide semiconductor substrate and a trench metal-oxide semiconductor field effect transistor, the field effect transistor includes a trench vertically arranged and penetrating along a first horizontal direction, a gate insulating layer formed on an inner wall of the trench, a first poly gate formed on the gate insulating layer, a shield region formed outsides and below the trench, and a field plate arranged between a bottom wall of the trench and the shield region, and the field plate has semiconductor doping and is laterally in contact to a current spreading layer to deplete electrons of the current spreading layer when a reverse bias voltage is applied.

Abstract: A method and a system for wireless positioning are provided. Multiple received signal strengths corresponding to multiple wireless access points are measured by a user device. The received signal strengths include multiple first received signal strengths. A reference positioning position is obtained according to positioning reference information provided by the user device. A first positioning position based on the first received signal strengths is obtained. The reference positioning position is compared with the first positioning position. In response to the distance between the reference positioning position and the first positioning position being greater than a tolerance value, at least one of the first received signal strengths is excluded from the multiple received signal strengths, so as to obtain multiple filtered received signal strengths. A user position of the user device is obtained according to the filtered received signal strengths.